How Can I See The Longest Total Eclipse Of The 21st Century?

A total lunar eclipse will be visible across much of the globe, including Australia.

Get ready to wake up early on Saturday morning if you want to see a deep red ‘blood moon’ as you look up to the skies.

On July 28 (AEST), the longest lunar eclipse of the 21st century will be visible across much of the globe, including Australia.

Lunar eclipses occur when the Earth moves directly between the sun and the moon. And while anywhere between one and four of these events take place each year, this one is particularly long (approximately 1 hour and 43 minutes) and special. Here’s why.

A 'super blue blood moon' seen in Rosaria, near Santa Fe, on January 31, 2018. Image: AAP

What is a lunar eclipse?

You may be aware of that faint, reddish glow, but what’s really going on here?

Put simply, an eclipse occurs when a planet or moon passes between another planet, the moon or the sun. During an orbit, Earth will once in a while line up directly between the sun and the moon, causing Earth’s shadow to cover the moon.

NASA tells us the moon’s red glow is caused by Earth completely blocking the sunlight that normally reflects off its surface.

A "super blue blood moon" is a combination of a supermoon, blue moon and lunar eclipse. This one is visible in India this January. Image: AAP

When and where can I catch it?

A lunar eclipse can last for up to several hours. This one will be visible for nearly four hours, as the moon passes through the centre of Earth’s shadow. Totality -- when it passes the darkest part of Earth’s shadow -- will last for about one hour and 43 minutes.

Different stages of the lunar eclipse will be visible at different times across the globe.

Western Australia will be the only state in Australia to catch the entire eclipse, with first glimpse expected around 3.14am (AEST) as it begins. The moon will start to turn red around 5.30am (AEST) as the total eclipse starts, and ends around 7.13am.